This invention relates to an improved process for upgrading hydrocarbon feed streams, especially heavy oils. In another aspect, this invention relates to a non-catalytic, non-extractive process for upgrading heavy oils.
It is well known that heavy crude oils, as well as products from extraction and/or liquefaction of coal and lignite, products from tar sands and oil shale and similar products may contain metals such as nickel and vanadium. The presence of these metals makes further processing of heavier fractions difficult since the metals generally act as poisons for catalysts employed in processes such as catalytic hydrodesulfurization, hydrogenation and catalytic cracking. It is further known that heavy oils are quite viscous due to the high content of high molecular weight carbonaceous materials called heavies. It is frequently necessary to break down a portion of these heavies in a pretreatment operation so as to facilitate the transport of heavy oils through pipelines to refineries.